1. Technical Field
The present invention generally relates to window coverings and more specifically to drapery assemblies.
2. Background Art
Drape assemblies are used to cover openings or fixtures such as windows, screens or stages and are well known in the prior art. FIG. 1 shows an illustrative drapery assembly 10 covering a window 11. Drape assemblies generally comprise a drapery rod 12 mounted on a surface from which a drape 13, often pleated fabric, is connected via a series of carriers. The carriers may simply be rings hanging on the drapery rod 12 or alternatively, a carrier configured to slide along the length of the drapery rod 12. The drape 13 is hung from each carrier by a connector, such as a hook or a clamp. A primary carrier 14 is attached to the foremost end of each drape and secondary carriers 15 are distributed along the length of the drape 13.
Large windows may be covered by multiple drapes if necessary. However, drape assemblies most commonly fall into one of two categories: single drape assemblies or double drape assemblies. Single drape assemblies include one drape which covers the entire opening. Double drape assemblies include two drapes, each covering half the opening. Each drape in a double drape assembly is attached to a primary carrier located at the foremost edge which closes toward and opens away from the center of the opening. The two primary carriers are usually mechanically synchronized to move in unison (i.e. both are opening or both are closing).
Drape assemblies may be controlled both manually and mechanically. The simplest method involves pulling a wand attached at the foremost end of the drape or pulling the drape itself. The secondary carriers are then pushed along the drapery rod by the primary carrier or pulled along the drapery rod by tension in the drape. Although this is a simple, low-cost option, there are significant disadvantages with opening and closing drapes in this manner. Manually pulling the drape requires someone to walk the length of the opening. Additionally, it may be impractical to close large drapes with a wand due to the weight of the drapes and the force required to overcome friction in a large number of secondary carriers. Finally, the tension in the drape required to move the secondary carriers along the drapery rod 12 when closing causes damage or premature wear in the drape.
Pulley operated drape assemblies, both manual and mechanical, are among the most popular types of drape assemblies employed. Most commonly, the primary carrier is attached to a drive cord that is guided inside the drapery rod. At each end of the drapery rod, the drive cord is normally guided through a free-wheel pulley at the non-drive end and through a drive pulley at the drive end. The drive cord may be manually operated or mechanically driven.
Motor powered drapery assemblies are known in either a direct drive version or an indirect drive version. Prior Art FIG. 1 shows a direct drive version of a motor driven pulley. In a direct drive version, the motor 16 is directly connected to the drapery rod 12 and the rotation power is transmitted to the drive cord 17 or belt via a gear mechanism. In indirect drive versions the motor is normally mounted at some distance below the drapery rod 12 and a vertical loop of the drive cord that extends below the drapery rod 12 is guided through a pulley attached to the motor. Indirect motors are more commonly used to retrofit manual cord driven drapery assemblies.
Those skilled in the art will recognize that despite their popularity there are significant disadvantages associated with pulley operated drape assemblies. Tension in the drape causes unnecessary wear and damage. The motors used are hard to conceal and are often noisy and distracting. Additionally, such systems are inefficient due to the indirect application of force and the friction of the pulleys and extra components. Finally, the friction and slippage in the pulleys causes the motion of the drape to be jerky and intermittent.
It is known in the prior art to directly drive the primary carrier of a drapery assembly with a motor mounted on the primary carrier. Zeeb (U.S. Pat. No. 5,676,189) discloses such a motorized drapery track assembly. The motorized drapery track assembly includes a motorized drive wheel receiving electric power through wires interconnected to the drapery trollies and controlled through external switches. Alternatively, the motorized drive wheel may be remotely controlled and receive electric power though a battery. The motorized drapery track assembly disclosed in Zeeb is particularly suited for traversing a curved track.
Those skilled in the art will recognize certain disadvantages to the prior art drapery track assembly. Routing wires along the length of the drapery rod is not aesthetically pleasing. This power and communication scheme may potentially cause mechanical malfunction as well. Wires routed in such a manner may easily become tangled in the drapery assembly components or surrounding environment. Even in the battery powered and remote controlled embodiment of the drapery track assembly, there are significant limitations. Control options are limited. Only the primary carrier may be controlled from the external switch and only by visually observing the moving primary carrier.